Meet our Software Provider Experts

Getting to Know Slot Providers

If you've spent any time within the online slots sector, then you'll be fully aware that there is a huge range of games to choose from. Slots make up the biggest portion of this games selection, and it's not uncommon to see hundreds or even thousands of titles available at any given site.

Slot game production has become an integral part of the online casino industry, with the best game developers conjuring games using so many different themes and topics. It's made the industry what it is and while trying to review as many as we can keeps us on our toes, it gives you, the players, as good a range as you've ever had. 

As you've surely noticed, slot sites offer a very similar range of games. This is because the casinos don't actually develop slot games themselves, but get them from third-party slot site software providers.

A slots site can pick and choose the casino software providers that it wants to use based on the database of games they have on offer. Best slot sites will generally take the full range of games, but not always, citing that some do not fit into the product that they want to offer.

Throughout this article, we talk more about how these slot software providers work and how they can offer some of the most engaging games in the industry. We will look at what works and what does not, but most importantly give you the tools to work out what's best for you. There is plenty of information about the iGaming software industry out there, but here we endeavor to sum up the best slot providers and slot software developers.

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How We Test and Review the Best Slot Software Providers

SlotSource's team of dedicated experts is focused on anything that has the word slots in it. They meticulously review slot providers, slot bonuses, new and classic slot games, as well as the companies behind those games. When reviewing slot game providers, here are some things we take into account:

  • Trustworthiness
  • Licenses
  • Awards
  • Reputation
  • RNG
  • Game selection
  • Innovations
  • Technology
  • User experience
  • Game design

Each game provider has a unique range of online casino games. Their catalog can include their own in-house creations, as well as slot games developed by other studios on their request. Sometimes, through acquisitions, a game provider may take ownership of games created by another software provider. A recent example is when Games Global bought Microgaming's portfolio of games.

Trustworthiness and Licensing

The history of the company is something that we look at closely. We want to know their background in gambling software and what they have in their arsenal that sets them apart from the competition. At the minute there is a nice mix of long-standing game providers and a host of new-age businesses jumping on the bandwagon of platforms such as HTML 5.

What a lot of people don't know is that each of these companies needs to be licensed to make their games. Each of their games are tested and verified by the regulating bodies.

A regulator's role is to look over each online slot game that is produced and make sure they are fair and hit the numbers that are reported. The game developer cannot miss this step. If they don't submit their creations for review, they will not be able to publish that slot game.

Awards and Reputation

Next up we like to see if the online gaming software provider has any awards from within the industry. Generally, an acknowledgment by their peers means they are creating good online games. If a wide variety of casino games is important for you when signing up at a new slots site, we'll leave some recommendations below.

Seeing which slot sites are hosting well-known game providers is another easy factor to see how good they are. If most of the top casinos are stocking their products, then you will likely see that they are worth investing in.

Game Selection and Innovation

Once the look into the business side of things is complete, it's now time to shift our look toward the games on offer. It's not just the volume of games here, although this is important. Quality is key because we want to make sure that the games we are recommending on SlotSource are of the highest standard. If they are not, we will tell you, don't worry.

Innovation within the sector is another crucial item. We have shifted a huge amount of time and resources into reviewing just this area, trying to highlight what these companies are doing to break the mold and try to become the best slots software provider.

Technology and User Experience

RTP (Return to Player) percentages and game volatility are key areas that take up a lot of our time. One thing we will point out in terms of RTP is that the best online slots aren't necessarily the ones with the highest RTP. There is a need to strike a balance between this number and the volatility of a slot that then makes an online slot "great". The better the balance between these two, the better for the player, for the most part at least. Both RTP and volatility are something to take into account if you plan on playing real money slots.

Game Design

Design and in-game features are the next sections that we look at. Do the games look good on a range of devices and do they offer a nice range of features that keep players coming back? Given there are so many games to choose from these days, if the answer is no to just one of these questions, then the slot game will not score well.

To wrap up our review on game providers, we move away from slots and see what other types of games they are offering. After all, the package here is important and if they stand out in another area, we want you to know about it.

We want to stress that each of our reviews is constantly changing. The best game developers are bringing games out weekly, so these all contribute to the overall score. It's worth bookmarking this page where we will highlight which games are new and from which slot sites you can access them.

Meet Our Software Provider Expert

Jim Tomlin

Jim Tomlin

With more than 20 years of experience in online gaming and Sports journalism, Jim has keenly tested, played and reviewed a multitude of slot games, looking for characteristics that differentiate them in terms of themes, features and jackpots before they reach the market. When Jim finds a slot game he likes, he just keeps on spinning, going for the win. Not much we can do about that!

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How Slot Software is Regulated and Tested

Regulation for any casino game is incredibly important, but even more so for slots given the number of games on offer. Before any game comes to an online casino, they are tested for fairness, and only then are they legally allowed to be added to a gaming catalog.

There are lots of companies that work within this sector but ultimately, they need to be tested and comply with a rating from the regulator. They make sure things like the mentioned RNG and RTP are both as have been reported and are fully fair.

eCogra is one of the most recognised independent testing bodies within the casino industry. The London firm has made it their job to test all games and make sure that they run as they should. Whilst there is no official tie to licensing bodies, eCogra works closely with them, flagging games that don't meet the criteria to them.

You will notice that most reputable casinos work with eCogra and they will highlight this within the casino. The same standards are followed with the game developers as well, which again, can be checked on their website.

Other testing agencies that offer unbiased certification of slot games include Quinel, iTechLabs and NMi Metrology.

Online gaming software providers are very conscious that even one flagged game is incredibly bad for business. There is no need to pull the wool over players' eyes given the margins that they get already, but as you can imagine, there are some that have and likely will try to in the future.

It's worth noting that the industry is as safe and fair as it's ever been regarding testing and fairness. The process to develop and license new games is not an easy one, with the right people looking to make sure that players are safe.

  • eCogra
  • Quinel
  • New Jersey Division of Gaming Enforcement
  • iTechLabs
  • GLI

Original and Innovative Game Providers

Slots make up the bulk of the games for the vast majority of game developers. They are relatively easy to make, and they can make slight adjustments to games to make them unique.

Over the years new innovations such as 3D slots and VR slots have been introduced to the market as software providers look to set themselves apart from the competition, and new features are constantly being worked on.

The theme is one of the most common and easiest things for a developer to change. The range now is crazy and some weird games are kicking about, with everything from lumberjacks to mermaids and monkeys to deep-sea divers.

Features within the games are another pretty customisable area. For this, things like paylines, bonus rounds and free spins make them stand out, with the more the better as far as we are concerned.

RTP is another factor that we love to see improved on and generally the higher the better. However, there needs to be a balance here between the RTP and the volatility of the game to avoid simply winning your stake back with each bet and getting nowhere fast. Most players would likely rather lose a little more for the thrill of hitting big.

Branded games have soared over the last 5 years and this, for us at least, is one of the most interesting sectors within online slots. This is because the game developer now has a brand image to take into account, but also likely a bigger budget to make these games as good as they can be.

You may notice from the list of providers and slots earlier in the article that lots of the games we recommend are branded slots. This is because they are generally better than your standard games, although not all have great RTP, so keep an eye out for that.

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Discover the Best Slot Game Developers for 2022

As you are about to find out, the range of slot software developers for players in the US is extensive. Below we have included a list of who we think is at the top of the pile right now.

Games Global

Although the name may not yet be very familiar, their vast catalog of games surely is. Games Global came onto the scene in 2021 after they acquired all the games created by industry giant Microgaming. With this move, Games Global ensured their presence on more slot sites than any other provider within the industry. With hundreds of games to choose from, they are one of the biggest, with legendary Microgaming slots including Mega Moolah (progressive jackpot), Jurassic Park and Game of Thrones.


The closest rival to Games Global? Maybe. But NetEnt slots are more than just a second-place contender and have been one of the best for several years now. Based in Sweden, the company have been able to produce a number of games that are now very much brands of their own. Two that stand out are that of Gonzo's Quest and Starburst. Both games are now heavily linked with many slot bonuses and welcome offers, with Starburst being the go-to game for most casinos that offer free spins bonuses. NetEnt has also been able to create one of the highest RTP's of any slot, with Mega Joker running at a massive 99% RTP.

Play’n GO

Another Swedish company that has been about since 1997, Play'n GO are not newcomers to this sector. However, it's only been over the last 5 years that we have seen them take their online casino games to the next level. Their hard work has paid off and Play'n GO slots like the Rich Wilde series and Troll Hunters are about as big an online slot as you will find in the business. They are best known for their stunning graphics and bonus rounds, making their games some of the most exciting on the market right now.


Another behemoth in the industry, Playtech boasts a massive 700 games in their catalogue and counting. They have been able to make a huge company from their success and they have over 5,000 employees based around the world. In terms of online casino games, it's the branded Playtech slots that have allowed the company to set them apart from the rest. There are countless ones on there, but links with the likes of DC Entertainment has seen games include Justice League, The Dark Knight, Superman, Age of Gods and many, many more.

Yggdrasil Gaming

Possibly the most underrated slots game developer in the game, Yggdrasil is killing it right now. They don't have the biggest range of online casino games to choose from, but they take quality over quantity to a new level. Opening their doors in 2013 means they are still relatively young, but they have taken the technological advancements of platforms like HTML 5 to new levels. Their Vikings Go series along with the likes of Blood Moon Wilds are not just some of the best slots on their platform, but in the industry.

ELK Studios

One of the middle-of-the-road game providers that are used as more of a filler than anything too dominant in the industry. They are another that is based out Sweden, but they work on a more limited budget and size than any of the aforementioned providers. However, they have some more than decent online slots, with the standout being that of Wild Torso. The slot was able to pick up Game of the Year at the EGR Operator Awards back in 2017, fighting off a lot of stiff competition from much bigger companies.


IGT is as big as they come when it comes to casino slot providers. They are the only one to have toppled the 1,000 mark when it comes to slots alone and also one of few that can power a full online casino on their own. The brand is huge and they have over 12,000 employees who are based all over the world. They still run a lot of brick and mortar slot machines, but in terms of their online portfolio, the best IGT slots include Da Vinci Diamonds, Family Guy and Cleopatra Plus.


One of the best game developers that is as well known for their land-based games as their online slots, Novomatic have been running since 1980. The company have been able to make the move from land to online and whilst they haven't seen the success that they might have hoped online, they are still pretty well known. The range of online casino games is a little limited, but their biggest game is by far that of the Book of Ra (rhyme unintentional). The game has been linked with a huge range of free spins offers from dozens of casinos over the years. Other Novomatic slots that stand out are Sizzling Hot, Dolphin's Pearl and Lord of the Ocean.

Nolimit City

With a catalogue of around 30 slots in total, Nolimit City is one of the smaller brands that are hooking up US players with casino games. They do pack a punch, however, and they are incredibly interactive working seamlessly on mobile and online platforms.


NextGen was originally set up down under in Australia and over the years have jumped about between acquisitions and takeovers of their own. This has enabled the company to invest large sums of money into their game development which has now paid dividends, as they've got a great arrange to choose from. Gorilla Go Wild and Jackpot Jester are two very popular NextGen slots. They both include a huge range of their features and bonus rounds, showcasing what NextGen is capable of.

Other Slot Software Developers for US Casino Players

Above we've included a range of the bigger developers in the industry, but there are dozens more that we could talk about as well. These are smaller companies, but they play an important role in making casinos as unique as they can be.

We spoke earlier about HTML 5 allowing companies to develop better games that work seamlessly on mobile, but it's also made it much easier to create these games as well. This has opened the door for what we like to call "independent game developers" who are not part of a bigger company.

They lack a little when it comes to the size and number of games, but as there are less to work on, it means that the quality is often really high. It's not uncommon for smaller developers to pick up wins for best-slot-type awards for this very reason.

What holds them back is trying to break into what is a pretty closed shop at the top of the tree. Casinos like to have a good stock of slots on offer, so when a company is pitching a catalog of 20 to 30 online casino games, it means more work for the casino to then get others in to pad out the rest of the site.

That being said, the smaller providers have to start somewhere, and we have been mightily impressed with some of the games that have been produced over the last few years. Below we have included a list of some of these casino software providers:

Leading Slot Software Producers for Mobile Casino

As the mobile sector continues to grow, so does the time and resources given to it from slot developers. Games are now created with a mobile-first approach such is the impact that mobile casino is having within the industry.

Developers have to be able to offer their games on both an app platform and a mobile browser platform. This is because many casinos can access both, which is why platforms like HTML 5 are so important as it allows the developer to do this.

What we are seeing is that the quality of these mobile slots is going through the roof. Some are even being made with a one-finger setup, meaning you can use the game as if you were scrolling through your social media accounts with one finger, instead of a landscape view as if you were getting ready to play a game. 

More people are playing on iPhone and Android devices than there are on more traditional desktops. This means the range of mobile slots will continue to rise. However, it is worth noting that not all games will be copied across. Games that are older and get little to no gameplay just aren't worth the time and money to make the change from online to mobile. This is something you need to be aware of, especially if you are clearing bonuses on mobile.

Progressive Jackpot Slot Developers

Progressive jackpots are what attract most people to slots. And the reason is simple. They offer the possibility to win impressive sums of money with a single spin. Some game suppliers specialize in progressive jackpot slots, just like another game provider might be more adept at developing a video slot. While the best game developers should offer all types of slot games, some specialize in a certain field of online gaming software.

These work as a cross-developer platform mostly and by this, we mean that the jackpots are run via the developer and not the casino they are hosted on. This means that a huge number of players get access to them and that's why the jackpots are so big.


One of the biggest of the progressive jackpot group is that of Microgaming. Their single biggest game is Mega Moolah with a top payout of almost $19 million from a single game. Other notable progressives include Major Millions, King Cashalot, Treasure Nile and Poker Ride.


NetEnt has a massive range to choose from here with over 80 progressive jackpot games spread out over several casinos. Its biggest win is almost $18 million which came on the Mega Fortune progressive. Other notable games include Hall of Gods, Mega Fortune Dreams, Arabian Nights, and Caribbean Stud.


Playtech has a more diverse range of progressive games and they include several table games within their section. As one of the biggest slots operator of them all, it will come as little surprise to hear that, but in terms of their biggest jackpot win, it's down on the others at "just" $9 million on Jackpot Giant. Other games include Beach Life, Gold Rally, Gladiator and Funky Fruits.


The smallest of our picks, Yggdrasil are down on numbers, but for us, have the best jackpot games of any of the competition in terms of playability and graphics. The one to watch is that of Joker Millions which as a top prize of $7.8 million.

New Slot Releases from Game Providers

In general, most of the top or more significant slot providers produce at least one slot per month, and our team at SlotSource test and review them so that we can recommend the best ones to our readers.

We also have a handy Slots Calendar with a list of new online slots which we built specifically for online slots fans to keep up to date with the latest drops. We recommend bookmarking that page so you never miss out on the latest releases, as well as details on upcoming games.

Slot Software Providers FAQ

What makes a slot provider better than others?

It comes down to the quality of games on offer and usually the budgets that are invested in each game. The likes of Games Global, NetEnt and Playtech have huge budgets which not only allow them to make good games but lots of them.

Which game providers produce the most profitable jackpot slots?

The biggest jackpot slot lists belong to Games Global (Microgaming), NetEnt, Playtech and Yggdrasil. It's tough to say which slot game provider might offer the most profitable slots, as most will have a mixture of different games with a variety of RTP rates.

Can I play new slots for free?

In the US it is only possible to try real money slots for free after you create a slot site account. Some slot sites will then allow you to access what is known as demo games, where you play the games for free.

Do slot developers need to be licensed in the US?

Yes, they must be fully licensed to be able to publish their games. Regulators work with companies like eCogra to ensure that the slots they develop comply with gambling laws and are safe and trustworthy. Rest assured, we do a full background check on all of the slot providers that we review.

Where can I play slots from the best software developers?

All of the top-recommended slot sites we list on SlotSource stock at least one of these game providers. This includes the likes of Party Casino, PlayZee, LeoVegas, Casino Nation and 888 Casino - but feel free to check out the reviews of any individual operator that tickles your fancy.

Which slot provider is considered the best?

It’s tough to say, but Games Global is probably regarded as one of the biggest and the best. This is based on the fact that they own Microgaming slots which are popular with all slot sites. A casino software provider's popularity can vary from country to country depending on the type of slots they have on offer.

Do slot sites feature all slot providers?

No, they will choose just several providers to power the slots site. The number will differ, but usually anywhere from 5 to as many as 30. Different slot sites will partner with different software game providers, so check out your chosen slot site's library before signing up to make sure they have teamed up with your favorite slot developer!

Which Game Provider has the most slots?

Playtech is the biggest in the industry right now with over 1,000 slots alone. Other industry leaders would include the likes of NetEnt, Games Global and Yggdrasil. Remember, however, that slot software developers will release new titles all the time, so their libraries are always expanding.

Do all slot software providers make mobile slots?

Most of them do, yes. However, not all games from their catalogues have been copied across to mobile basically because not enough people play those games to warrant the cost of changing over, but in general, most slots are optimised for mobile devices.

Which Software Provider is known for largest winnings?

In general, Games Global is considered one of the leaders for providing players with the largest wins, with plenty of progressive jackpot slots in their library including the super popular Mega Moolah that has paid out millions in the past.

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